Display panel and manufacturing method thereof

ABSTRACT

A display panel includes a substrate, a plurality of thin film transistors (TFTs), a plurality common electrodes, a plurality of common electrode lines, a plurality of coupling electrodes, and a plurality of pixel electrodes. Each of the TFTs comprises a gate, a source, a drain and a channel layer coupling the source to the drain. The gate, the common electrodes, and the common electrode lines are formed on a surface of the substrate and are separated from each other. Each of the coupling electrodes couples a corresponding common electrode to a corresponding common electrode line, and a space is defined between the corresponding common electrode and the corresponding common electrode line.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. Ser. No.14/750,177, filed Jun. 25, 2015 the contents of which are herebyincorporated by reference. The patent application Ser. No. 14/750,177 inturn claims the benefit of priority under 35 USC 119 from Chinese PatentApplication No. 201410434066.1 filed on Aug. 29, 2014.

FIELD

The subject matter herein generally relates to a display panel a methodfor manufacturing the display panel.

BACKGROUND

In-plane switching (IPS) mode liquid crystal display (LCD) panels arebecoming more and more popular because they can present a wider viewingangle to a viewer than twisted nematic (TN) mode LCD panels. Generally,in a method for manufacturing the IPS mode LCD panel, a plurality ofphotomask may be used in different photo etching processes (PEPs) toform different circuit patterns of the IPS mode LCD panel.

BRIEF DESCRIPTION OF THE DRAWINGS

Implementations of the present technology will now be described, by wayof example only, with reference to the attached figures.

FIG. 1 illustrates a partial plan view of a display panel having adisplay area and a border area.

FIG. 2 illustrates is a cross-sectional view taken along line II-II ofFIG. 1.

FIG. 3 is an enlarged view of a circle region III of FIG. 2.

FIG. 4 illustrates a flowchart of a method for manufacturing the displaypanel 1 of FIG. 1 and FIG. 2.

FIG. 5 illustrates a diagrammatic view of a metal layer is formed on asubstrate and a first photoresist layer is formed on the metal layer.

FIG. 6 illustrates a diagrammatic view of an exposure and developmentprocess is performed to pattern the photoresist layer.

FIG. 7 illustrates a diagrammatic view of a plurality of photoresistpatterns are formed on the metal layer.

FIG. 8 illustrates a diagrammatic view of a plurality of gates and aplurality of common electrode lines are form on the substrate.

FIG. 9 illustrates a diagrammatic view of a layer of conductivematerials is coated on the substrate and the photoresist patterns.

FIG. 10 illustrates a diagrammatic view of the photoresist patterns anda portion of the conductive materials on the photoresist pattern areremoved from the substrate.

FIG. 11 illustrates a diagrammatic view of a second photoresist layer isformed on the substrate and covers the gates, the common electrodes, andthe common electrode lines.

FIG. 12 illustrates a diagrammatic view of a portion of the secondphotoresist layer corresponding with the border area BB is removed.

FIG. 13 illustrates a diagrammatic view of a portion of the conductivematerials corresponding with the border area of the display panel isremoved.

DETAILED DESCRIPTION

It will be appreciated that for simplicity and clarity of illustration,where appropriate, reference numerals have been repeated among thedifferent figures to indicate corresponding or analogous elements. Inaddition, numerous specific details are set forth in order to provide athorough understanding of the embodiments described herein. However, itwill be understood by those of ordinary skill in the art that theembodiments described herein can be practiced without these specificdetails. In other instances, methods, procedures, and components havenot been described in detail so as not to obscure the related relevantfeature being described. The drawings are not necessarily to scale andthe proportions of certain parts may be exaggerated to better illustratedetails and features. The description is not to be considered aslimiting the scope of the embodiments described herein.

The term “coupled” is defined as connected, whether directly orindirectly through intervening components, and is not necessarilylimited to physical connections. The connection can be such that theobjects are permanently connected or releasably connected. The term“comprising”, when utilized, means “including, but not necessarilylimited to”; it specifically indicates open-ended inclusion ormembership in the so-described combination, group, series and the like.

The present disclosure is described in relation to a display panel and amethod for manufacturing the same.

Referring to FIG. 1 and FIG. 2, FIG. 1 illustrates a partial plan viewof a display panel 1, FIG. 2 is a cross-sectional view taken along lineII-II of FIG. 1. In at least one embodiment, the display panel 1 caninclude a substrate 11, a plurality of gate lines 10, a plurality ofdata lines 12, a plurality of thin film transistors (TFTs) 13, aplurality of common electrodes 14, a plurality of common electrode lines15, a plurality of coupling electrodes 16, and a plurality of pixelelectrodes 17. The display panel 1 can be composed of a display area AAand a border area BB (also called non-display area or non-active area)surrounding the display area AA.

The gate lines 10 and the data lines 12 are intersected with each otherto define a plurality of pixel units 40 within the display area AA. Atleast one of the common electrode line 15 is located in each of thepixel units 40. In at least one embodiment, the gate lines 10 arearranged in parallel, the data lines 12 are arrange in parallel as wellas the gate lines 10, and the common electrode lines 15 are alsoarranged in parallel. The common electrode lines 15 can be in parallelwith the data lines 12. The gate lines 10 can extend along a firstdirection while the data lines 12 can extend along a second directionperpendicular with the first direction. Thus, the pixel unit 40 isrectangular. Each pixel electrode 17 is located within a correspondingpixel unit 40 and is electrically coupled to corresponding TFT 13. Thepixel electrode 17 can be made of transparent materials, such as indiumtin oxide (ITO).

The common electrode 14 can be located in the display area AA of thedisplay panel 1. The common electrode 14 is coupled to the at least onecommon electrode line 15 within a corresponding pixel unit 40 via acorresponding electrode 16, but the common electrode 14 is not contactedwith the at least one common electrode line 15 within the correspondingpixel unit 40. In this embodiment, since short circuit issues may happenin the border area BB if the common electrode lines 15 extend to theborder area BB, the common electrode lines 15 are located within thedisplay area AA.

Each of the TFTs 13 is located in a corresponding pixel unit 40 and iscoupled to a corresponding gate line 10 and a corresponding data line12. Each TFT 13 can include a gate 130, a gate insulation layer 132, asource 134, a drain 136, a channel layer 137 and a flat layer 138. Thechannel layer 137 is coupled between the source 134 and the drain 136.In at least one embodiment, the TFTs 13 can be bottom-gate TFTs.

The gate 130 is formed on the substrate 11 and is coupled with acorresponding data line 10. The common electrodes 14 and the commonelectrodes lines 15 both are formed on the substrate 11 as well as thegate 130. The gate 130, the common electrodes 14, and the commonelectrode lines 15 are separated from each other to avoid electricalconnections therebetween. The gate insulation layer 132 is coated on thesubstrate 11 and covers the gate 130 of each TFT 13, the commonelectrodes 14, and the common electrode 1 lines 15.

The channel layer 137 is located on the gate insulation layer 132 andcorresponds with the gate 130. The source 134 and the drain 135 areformed on the gate insulation layer 132 and are respectively coupled atopposite sides of the channel layer 137. The source 134 is coupled to acorresponding data line 12.

The flat layer 138 is coated on the gate insulation layer 132 and coversthe channel layer 137, the source 134 and the drain 136. The flat layer138 defines a plurality of first contact holes 1380 and a plurality ofsecond contact holes 1382 respectively corresponding with the drain 136of each of the TFTs 13 and the common electrode lines 15. The pixelelectrode 17 is coupled to the drain 136 via the first contact hole1380. The coupling electrode 16 is coupled between a correspondingcommon electrode 14 and a corresponding common electrode line 15 via thesecond contact hole 1382. In this embodiment, as shown in FIG. 3, aspace S is defined between the corresponding common electrode 14 and thecorresponding common electrode line 15, thereby separating thecorresponding common electrode 14 from the corresponding commonelectrode line 15.

Each pixel electrode 17 defines a plurality of slits 170 to corporatewith the common electrode 14 within a corresponding pixel unit 40 toform a parallel electrical field. Thus, the display panel 1 can be anin-plane switching (IPS) mode liquid crystal display (LCD) panel.

FIG. 4 illustrates a flowchart of a method for manufacturing the displaypanel 1 of FIG. 1 and FIG. 2. The method is provided by way of example,as there are a variety of ways to carry out the method. Each block shownin FIG. 4 represents one or more processes, methods, or subroutineswhich are carried out in the example method. Furthermore, the order ofblocks is illustrative only and the order of the blocks can change.Additional blocks can be added or fewer blocks may be utilized withoutdeparting from the scope of this disclosure. The example method canbegin at block 301.

At block 301, a substrate 11 is provided. The substrate can be atransparent substrate such as glass substrate or a plastic substrate. Inother embodiments, the substrate 11 can be a translucent substrate, anon-transparent substrate or a flexible substrate.

At block 302, as shown in FIG. 5, a metal layer 22 is formed on thesubstrate 11 and a first photoresist layer 25 is formed on the metallayer 22

At block 303, referring to FIG. 6 and FIG. 7, the first photoresistlayer 25 is patterned by an exposure and development process using aphotomask 23 to form a plurality of photoresist patterns 250 on themetal layer 22. The photomask 23 can be made of metal materials.

At block 304, as shown FIG. 8, the metal layer 22 is etched to form aplurality of gates 130 and a plurality of common electrode lines 15 onthe substrate 11 which are covered the photoresist patterns 250. In thisembodiment, only one gate 130 and one common electrode line 15 are shownin FIG. 8. Each gate 130 and each electrode line 15 are covered by thephotoresist patterns 250. In at least one embodiment, the metal layer 22can be etched by an over etching process. Thus, an area of the gate 130is less than an area of a corresponding photoresist pattern 250 whichcovers the gate 130. For example, as shown in FIG. 8, a distance β isdefined between an edge the gate 130 and a corresponding edge of thephotoresist pattern 250 which covers the gate 130. Accordingly, an areaof the common electrode line 15 is less than that of a correspondingphotoresist pattern 250 which covers the common electrode line 15.

At block 305, as shown in FIG. 9, a layer of conductive materials 140 iscoated on the substrate 11 and the photoresist patterns 250. In thisembodiment, the layer of conductive materials 140 is coated on surfacesof the photoresist patterns 250 away from the substrate and is coated ona portion of a surface of the substrate 11 which is not covered by thephotoresist patterns 250. The conductive materials 140 can betransparent conductive materials, such as transparent conductive filmsmade of indium tin oxide (ITO). The conductive materials 140 serve ascommon electrodes 14 of the display panel 1. Since a distance β isdefined between an edge of the gate 130 and a corresponding edge of thephotoresist pattern 250 which covers the gate 130, the conductivematerials 140 will not contact with the gates 130. Further, since thearea of the common electrode line 15 is less than that of acorresponding photoresist pattern 250 covering the common electrode line15, the conductive materials 140 will not contact with the gates 130.

At block 306, as shown in FIG. 10, the photoresist patterns 250 and aportion of the conductive materials 140 on the photoresist pattern 250are removed from the substrate 11. Thus, the other portion of theconductive materials 140 maintained on the substrate 11 form the commonelectrodes 14.

At block 307, as shown in FIG. 11, a second photoresist layer 35 isformed on the substrate 11 and covers the gates 130, the commonelectrodes 14, and the common electrode lines 15.

At block 308, as shown in FIG. 12, a portion of the second photoresistlayer 35 corresponding with the border area BB is removed. In at leastone embodiment, an exposure process is first performed to expose thesecond photoresist layer 35 from a side of the substrate 11 away fromthe second photoresist layer 35 using an ultraviolet photomask 26, andthen a development process is utilized to remove the portion of thesecond photoresist layer 35 corresponding with the border area BB.

At block 309, as shown in FIG. 13, a portion of the conductive materials140 corresponding with the border area BB is removed by an etchingprocess. Then, the other portion of the second photoresist layer 35coated on the substrate 11 corresponding with the display area AA isremoved to expose the common electrodes 14 in the display area AA.

At block 310, a gate insulation layer 132 is formed on the substrate 11to cover the gates 130, the common electrodes 14, and the commonelectrode lines 15.

At block 311, a plurality of channel layers 137 are formed on the gateinsulation layer 132 corresponding with the gates 130.

At block 312, a plurality of sources 134 and drains 136 of the TFTs 13are respectively formed on the gate insulation layer 132. The source 134and the drain 136 are respectively coupled at opposite sides of acorresponding channel layer 137.

At block 313, a flat layer 138 is formed on the gate insulation layer132 to cover the channel layers 137, the sources 134, and the drains136.

At block 314, a plurality of first contact holes 1380 corresponding withthe drains 136 and a plurality of second contact holes 1382corresponding with the common electrode lines 15 and the commonelectrodes 14 are formed on the flat layer 138.

At block 315, a plurality of pixel electrodes 17 and a plurality ofcoupling electrodes 16 are formed on the flat layer 138. Each pixelelectrode 17 is electrically coupled with a corresponding drain via acorresponding first contact hole 1380. Each coupling electrode 16 iscoupled with a corresponding common electrode 14 and a correspondingcommon electrode line 15 via a corresponding second contact hole 1382,thereby making an electrical connection between the corresponding commonelectrode 14 and the corresponding common electrode line 15.

As described above, the gates 130 and the common electrodes 14 can beformed in a same exposure process using the photomask 22. Therefore, thecost for manufacturing the display panel 1 in the above mentioned methodcan be decreased compared with a traditional manufacturing method of thedisplay panel 1.

What is claimed is:
 1. A display panel comprising: a substrate, aplurality of thin film transistors (TFTs), a plurality commonelectrodes, a plurality of common electrode lines, a plurality ofcoupling electrodes, and a plurality of pixel electrodes, wherein eachof the plurality of TFTs comprises a gate electrode, a source electrode,a drain electrode and a channel layer coupling the source electrode tothe drain electrode; the gate electrode, the common electrodes, and thecommon electrode lines are formed on a surface of the substrate and areseparated from each other; each of the coupling electrodes couples acorresponding common electrode to a corresponding common electrode line,wherein a space is defined between the corresponding common electrodeand the corresponding common electrode line.
 2. The display panelaccording to claim 1, wherein the common electrodes are made oftransparent conductive materials.
 3. The display panel according toclaim 2, wherein each of the pixel electrodes defines a plurality ofslits to corporate with the common electrodes to form a parallelelectrical field.
 4. The display panel according to claim 1, wherein thecommon electrodes are made of transparent conductive films.
 5. Thedisplay panel according to claim 1, wherein the display panel comprisesa display area and a border area surrounding the display area, and thepixel electrodes are located in the display area.
 6. The display panelaccording to claim 5, further comprising a plurality of gate lines and aplurality of data lines, the plurality of gate lines and the pluralityof data lines are intersected with each other to define a plurality ofpixel units in the display area, and each of the plurality of TFTs islocated in a corresponding pixel unit and is coupled to a correspondinggate line and a corresponding data line.
 7. The display panel accordingto claim 6, wherein at least one of the common electrode lines islocated within each of the pixel units and is parallel with the datelines.
 8. The display panel according to claim 1, wherein furthercomprising a flat layer which covers the channel layer, the sourceelectrode, and the drain electrode of each of the TFTs, the flat layerdefines a plurality of first contact holes, each of the plurality offirst contact holes is between one of the plurality of common electrodelines and one of the plurality of common electrodes, each of theplurality of coupling electrodes is coupled between the correspondingcommon electrode and the corresponding common electrode line by one ofthe plurality of first contact holes.
 9. The display panel according toclaim 8, wherein the flat layer defines a plurality of second contactholes, each of the plurality of pixel electrodes is coupled to the drainelectrode of a corresponding TFT by one of the plurality of secondcontact holes.
 10. The display panel according to claim 1, wherein thedisplay panel is an in-plane switching (IPS) mode liquid crystal display(LCD) panel.